Telephone system



Aprfl 29,, 1924. 1,492,213

L. A. MORTIMER TELEPHONE SYSTEM Filed Dec. 29 1919 -4 Sheets-Sheet 1 ln van for Lou/'5 A. Morf/mcr April 29, 1924.

L. A. MORTIMER TELEPHONE SYSTEM 4 Sheets-Sheet 2 ed Dec 29 1919 Fig.2

April 29, 1924- L. A. MORTIMER TELEPHONE SYSTEM Filed Dec. 29 1919 4 Sheets-Sheet 5 76 Opcr afom April 29, 1924. 1,492,213

| A. MORTIMER TELEPHONE SYSTEM Filed Dec. 29 1919 4 Sheets-Sheet 4 #20)! //7 ver; /27/'.'

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raranrorricnx LOUIS A. MORTIMER, on NEW YORK, N. Y., AssmNoIrrro WESTERN-ELEGTRIG cora- PANY, INCORPORATED, on NEW YORK, Y., A CORPORATION on NEW YORK.

TELEPHONE SYSTEM. J

Application filed December 29, 1919 .Serial No. 347,831.

T all whom it may concern:

Be it known that I, LOUIS A. MORTIMER, a citizen of the United States, residing at New York, in the county of New York,

State of New York, have invented certain new and useful Improvements in Telephone Systems, of which the following is a full, clear, concise, and exact description.

This invention relates to an improved 10 method and means for signaling over transmission lines and has particular reference to such method and means as applied to telephone systems. 1

In systems of this nature, it has been pro 5 posed to employ physical and phantom lines for interconnection between distant olhces.

It has also been proposed to employ-these lines for the transmission of current im-- pulses of various natures to signal operators at the distant olhces and to control the operation of repeater apparatus at intermediate OfilCGS. I

An object of the invention is to render effective a plurality of repeaters by transmit ting an impulse over any one of a number cord circuits employed in connection with 1 the invention. 7

The invention is shown as consisting of physical lines A and C and a phantom line B interconnecting twodistant ollices W and Z and two intermediate o-llices or stations X and Y. A signaling circuit is simplexe'd with windings of repeating coils of line A; and is utilized for the purpose of transmitting signaling. impulses upon the initiation ortermination of a call on eitheryot ,the

lines A or' B., Such impulses also render is likewise simplexed with windings of repeating coilsjof line C, and impulses are transmitted over said c1rcu1t for signaling theoperator at a distant ofiice or for. dis-- abling the battery supply for the, filaments of telephone repeaters, HA1 and RC1 associated with saidlines A and C at oihce X, and: RAQ and RCQassociated withsaid lines at oilice Y when all the lines become idle. The telephonerepeaters arenotshown in detail sincetthey' may be ofany usual t pe suchas those employing vacuum tubes; o' larizedi relays 5 and 6 at oilice X are placed in series, respectively, with the signaling circuits associated with lines A and C, and, the operation of either of said relays, in re sponsetov a signaling or selective impulse transmitted for any one of the lines, controls a common. relay 7, whereby battery supply isconnected'tothe filaments of the repeaters at saidoffice to render the same effectivel' The repeaters HA2 and RCQat. oiiice Y are controlled by a common relay 9O 'which'is responsive toxthe energi'zation o'fapolarized rela s 81 and 91 on calls initiated at ofiice l/ and polarizedrelays86 and 96 on calls initiated at oiiice Z; Relays; 81 and 86. are arranged in the signaling circuiti associated with the physical line A, and also'co'ntrol the signalrepeating relays 82, S3, 84 and 85, while relays 91 and 96 are in series-with the signaling circuit connected to physical line C, and in a similar manner control signal repeating relays 92, 93, 94; and 95." The circuit arrangement at office Z is similar in allrespects to that at office whereby signals may be. received and transmitted therefrom in the same mannerasat office W. Thesignaling circuits also include polar relays 3,4 and-74 at Office W and similar relays 134 and 174 at office Z selectively responsive in each case to the impulses transmitted from the other oflice. It is believed that the invention will now be fully understood from the following detailed description of the operation.

Operator at 0777. 06 W initiates a call over line A The operator at oflice X desiring to extend a call to the olrlce Z, or desiring to communicate with the operator at the latter oflice, inserts plug 13 of a link circuit D at oflice WV into jack 20 of line A, relays 14 and 21 operating over a circuit extending from battery through the winding of relay 14 of the selected link circuit, the sleeve contacts of plug 13 and jack 20 and the Winding of relay. 21 to ground. Relay 3O thereupon operates" over a circuit ex tending from battery through the winding of relay 30,- the right-hand normal contact of relay 29, the left-hand normal contact of relay 28 and the right-hand alternate contact of relay 21 to ground. Relay 29 thereupon operates over a circuit extending from battery through the alternate contact of relay 30, winding of relay 29 and the right-hand normal contact of relay 50 to ground. The operation of relay 29 releases relay 30, but since relay 29 is slow to release, relay 28 operates over a circuit extending from battery through the left hand normal contact of relay 30, the righthand alternate contact of relay 29, the middle normal contact of relay 28, winding of relay 28, themiddle normal contact of re lay 30, and the right-hand alternate contact of relay 21 to ground. Relay 28 locks over a circuit extending from battery through the right-hand alternate contact.

and winding of relay 28, the middle normal contact of relay 30, and the right-hand alternate contact of relay'21 to ground. During the period that relay 29 is operated, a circuit is completed from the positive terminal of the 120 volt source of current, through the contact of relay 27, the lefthand alternate contact of relay 29, the upper bridged winding of relay 34, the simplexed conductors of line A extending from office W to office X, the winding of relay 5, the simplexed conductors of line A extending from office X to ofiice Y, and the winding of relay 81 to ground, at the normal contact of relay 85. The direction of current flow in this circuit is such that relay 5 closes its right-hand contact and relay 81 closes its lower contact. In closing its right-hand contact relay 5 causes the operation of relay 7 over an obviouscircuit and the closure of the right-hand and middle contacts of relay 7 completes the filament current supply circuits for repeaters BAland RC1, associate with line circuits A and C respectively. Relay 7 looks over a circuit extending from battery through the Winding and left-hand contact of relay 7 and the contact of relay 8 to ground. Relay 81 in closing its lower contact causes the operation of relay 83 over an obvious circuit. The closure of the left-hand contact of relay 83 causes the operation of relay 90 over an obvious circuit and the closure of the middle. and right-hand contacts of re lay 90 in a similar manner completes the filament battery supply circuits for repeaters HA2 and RC2 associated with the lines A and C, respectively, at oflice Y. Relay 9O locks over a circuit extending from battery through, the Winding and left-hand contact of relay 90, the right-hand normal contact of relay 94, and the left-hand normal contact of relay 92 to ground. Relay 81 releases upon the cessation of the impulse being transmitted, but during the period that the lower contact thereof is closed, relay 83- in closing its right-hand alternate contact establishes a circuit extending from positive terminal of the 120 volt source of current through the right-hand alternate contact of relay 83, the normal contact of relay 82, the upper bridged winding around the relay 86, the simplexed conducto-rs of line circuit A extending from office Y to ofiice Z and the winding of relay 134 to ground at the righthand contact of relay 149. The direction of current flow in this circuit is such that relay 134 closes its lower contact, completing a circuit extending from battery through the winding of relay 126, the right-hand normal contact of relay 121 and the lower contact of relay 134 to ground. Lamp 128 is thereby lighted over an obvious circuit and relay 127 is operated over a circuit extending from battery through the winding of relay 127, lefthand alternate contact of relay 126, and the left-hand normal contact of relay 121 to ground. The operatio-n'of the relay 127 prevents the transmission of a signal from oflice Z to office W. After the transmission of the impulse, relays 28 and 21 at oflice XV remain operated and relays 126 and 127 at oflice Z remain operated.

In response to the closure of the middle alternate contact of relay 21, relay 1 operates over an obvious circuit, causing the operation of slow-release relay 2 over an obvious circuit, thus' removing the ground connection at relay 2 for the operating circuit of relay 74, and preparing a circuit for disabling the telephone repeaters.

Operator at ofiice Z answers the call received over line A.

The operator at office Z observing the lighted condition of lamp 123, inserts plug 13 of a link circuit D at olfice Z'into jack 120, causing the operation of relays 14 and 121 7 130 over a circuit extending from grounded battery through the winding of relay 130, the left hand normal contact of relay 129, the righthand normal contact of relay 128, and the left hand alternate contact of relay "121 to ground. The operation of relay 130 closes an operating circuit for relay 129. ex-

tending from grounded battery through the right hand alternate contact of relay 130, the winding of relay 129 and the left hand normal contact of relay 150 to ground. Re-

a locked in an operated condition.

lay 129 thereupon looks over a circuit extending from battery through the left hand normal contact of relay 128, the middle alternate contact and winding of relay 129 and the left hand normal contact of relay 150 to ground. The opening of the left hand nor-- mal contact of relay 129, opens the circuit of and causes the release of relay 130, whereupon relay 128 operates over a circuit extending from battery through the right hand normal contact of relay 180, the left hand alternate contact of relay 129, the middle contact of relay 128 and the winding thereof the middle contact of relay 130 and the left hand alternate contact of relay 121 to ground. The opening of the left hand normal contact of relay 128 causes the release of relay 129. However, during the period in which the relay 129 is operated, a. circuit is completed extending from the positive terminal of the 120 volt source of current through the contact of relay 127, the right hand alternate contact of relay 129, the upper bridged winding around relay. 134, the simplexed conductors of line circuit A extending from office Z to ofiice Y, winding of relay 86, the lower bridged winding around relay 86, and the normal contacts of relays 82 and 83 to ground. Relay 86, in response to the current flowing over such circuit, closes its lower contact, causing the operation of relay over an obvious circuit. The closure of the right hand alternate contact of relay 85 producesno material effect upon the circuit since relay has been previously The 010-, sure of the left hand alternate contact of relay 85, however, completes a circuit during the continuation of they impulse which extends from the positive terminal of the volt source ofcurrent through the left hand alternate contact of relay 85, left hand nor mal contact of rela 84, the u or brid ed,

winding around relay 81, the simplexed conductors of line circuit A extending from oflice Y to o mce X, the winding of relay 5,

the simplexed conductors of circuit. A.

extending from ofiice X to oflice W, i the winding of relay 34, the lower bridged winding around said relay, the left hand normal contact of relay 29 and the left hand normal contact of relay 49, to ground. Although relay 5 closes its right hand contact in re, sponse to the current flowing there-through,

no material effect is produced upon the system, since relay 7 remains locked overa circuit previously described. The direction of current flowing through the winding of relay 34 is such that the lower contact thereof is closed, causing the operation of relay 24 over a circuit extending from battery through the winding of relay 24,'the left hand alter nate contactof relay 21, and the lower contact of relay 34 to ground. The operation of relay 24 connects a source of ringing current to the line and link circuit which will give a momentary audible signal to the'operator at ofiice W, whose listening key 15 is actuated at this time to indicate that the oporator at oflice Z has responded byinserting a plug into jack 120. The operator at office Z may converse with the operator at officeW by the actuation of listening key 15v in the link circuit associated with line circuit A, which connects the operators telephone set (not shown) to the associatedlink circuit in the usual manner.

Operator at 077900 W initiates a call one? Zine circuit 3.

tery through the winding of relay 50, righthand normal contact of relay 49, the lefthand normal contact of relay 48 andthe right-hand alternate contact of relay 41 to ground. Relay 49 thereupon operates over a circuit extending from battery through the alternate contact of relay 50, the winding of relay 49, and the right-hand normal contact of relay 30 to ground. Relay 49 locks over a circuit extending from battery through the right hand normal contact of relay 48, the middle alternate contact and winding of relay 49, and the right-hand normal contact of -relay"30 to ground. The operation of relay 49 opens the circuit for relay 50 caus ing the release thereof which causes the op eration of relay 48 over a circuit extending from battery through the left-hand normal contact ofrelay 50, the right-hand alternate contact of relay 49, the middlenormal contact and Winding of relay 48, the middle norllt) mal contact of relay 50 and the right-hand alternate contact of relay 41 to ground. Relay 48 locks over a circuit extending from battery through the right-hand alternate contact and Winding of relay 48, the middle normal contact of relay 50 and the righthand alternate contact of relay 41 to ground. In operating, relay 48 releases relay 49. However, during the period that relay 49 remains operated, a circuit is established from the negative terminal of the 120 volt source of current, through the contact of relay 47, the left-hand alternate contact of relay 49, the left-hand normal contact of relay 29,

I the upper bridged Winding around relay 34,

the simplexed conductors of line circuit A ext-ending from oliice W to oilice X, the Winding of relay 5, the simplexed conductors of line circuit A extending from otfice X to otfice Y, and the Winding of relay 81 to ground at the normal contact of relay 85. The direction of current flow in this circuit is such that relay 5 closes its left-hand contact and relay 81 closes its upper contact. The operation of relay 5 at this time has no effect upon the system since relay 7 is locked in an operative condition. The closure of the upper contact of relay 81, however, causes the operation of relay 82 over an obvious circuit. The closure of the left-hand alternate contact of relay 82 produces no material effect upon the system since relay 90 has been previously operated and remains locked in an operated condition, but the closure of the right-hand contact of relay 82 completes a circuit fromthe negative ter minal of the 120 Volt source of current through the right-hand alternate contact of relay 82, the upper bridged Winding around relay 86 the simplexed conductors of line circuit A extending from otiice Y to ofiice Z and the Winding of relay 134 to ground at the right-hand contact of relay 149. The direction of current flow through this circuit during t-he'period of transmission of the impulse, is such that relay 134 closes its upper contact thereby operating relay 146 over a circuit extending from battery through the Winding of relay 146, righthand normal contact of relay 141, and the upper contact of relay 134 to ground. Relay 146 is looked over a circuit extending from battery throughthe Winding and left-hand contact of relay 146 and the left-hand normal contact of relay 141 to ground. Lamp 143 is lighted over an obvious circuit to signal the operator that a call is being extended over the phantom line circuit B. The closure of the left-hand cont-act of-relay 146 operates relay 147 over a circuit ext-ending from battery through the Winding of relay 147, the left-hand contact of relay 146 and the lefthand normal contact of relay 141 to ground. After the impulse has been transmitted, relays 41 and 48 at oflice W are in an operated condition While relays 146 and 147 at office Z are in an operated condition.

Operator at ofiice Z answers a call initiated one?" Zine B.

sleeve contacts of plug 13 and jack 140 and WlHCliR of relay 141 to ground. The opening of the left-hand normal contact of relay 141 releases relays 146 and 147, thereby extinguishing lamp 143. A signaling impulse to inform the operator at oflice W that the operator at ofiice Z has answered the call is transmitted in the same manner as hereinbefore set forth in connection with line A. The relay 44 is operated in this instance, as will more clearly appear in the following description of the transmission of a disco n nect signal from oiiice Z to oiiice WV. the actuation of listening key 15 in the link circuit D, associated with the line circuit B at otiice Z, the operator thereat may communicate with the operator at office W over the phantom line circuit B which is-composed of physical lines or side circuits A and C.

Opera-250i" at ofiice W initiates a call one? line C'ii'cntt 0.

right-hand normal contact of slow-releasing,

relay 69, the left-hand normal contact of relay 68 and the right-hand alternate contact of relay 61 to ground. Relay 69 thereupon operates over a circuit extending from battery through the alternate contact of relay 70 and the Winding of relay 69 to ground. Relay 69 thereupon looks over a circuit extending from battery through the right-hand normal contact of relay 68, and

the middle alternate contact and Winding of relay 69 to ground. The opening of the right-hand normal contact of relay 69 causes the release of relay 70 so that relay 68 is operated over a circuit extending from battery through the left-hand normal contact of relay 70, the right-hand alternate contact of relay 69, the middle normal contact and Winding of relay 68, the right-hand normal contact of relay 70, and the right- Upon hand alternate contact of relay 61 to ground. Relay 68 in operating locks over a circuit extending from battery through the righthand alternate contact and winding of relay 68, theyright-hand normal contact of relay 70, and the right-hand alternate. contact of relay 61 to ground. .Relay 69 is thereupon released due to the opening of the right-hand normal contact of relay 68. However, during the period that relay 69is in an operated condition a circuit is established from the positive terminal of the .120

volt source of current, through the contact of relay 67, theleft-hand alternate contact of relay 69, the upper bridged Winding around relay 7 1, the simplexed conductors of line circuit C extending from office W to ofiice X, the winding of relay 6, the simplexed conductors of line circuit C extending from ofiice X to oilice Y, and the winding of relay 91 to ground at the normal contact of relay 95. I The direction of current flow in this circuit is such that relay 6 closes its left-hand contact and relay 91 closesits lower contact. The operation of relay 6 produces no material efiect on the system since relay 7 is locked in an operative condition due to the previous calls which have been transmitted over line circuits A and B. However, during the period that the impulse is being transmitted in connection with the call being extended over the line circuit C, relay 93 operates over an obvious circuit to complete a circuit for operating relay 90, but inasmuch as this relay is already locked, the operation of relay 93 has no effect thereon. Relay 93 also completes a circuit extending from the positive terminal of the 120 volt source of current through the righthand alternate contact of relay 93,'the righthand normal contact of relay 92, the upper winding bridged around relay 96, the sim-; plexed conductors of line circuit C extending from ofiice Y to oiiice Z, the winding of relay 174 and the lower winding, bridged therearound the right-hand normal contact of relay 169 and the left-hand alternate contact of relay 101 to ground. The direction of current flow through thiscircuit is such that relay 17 41 closes its lower contact thereby causing the operation of relay 166 over a circuit extending from battery through the winding of relay 166, the right-hand normal contact of relay 161 and the lower contact of relay 17a to ground. Lamp 163 is thereupon lighted over an obvious circuit and relay 167 is operated over a circuit extending from battery through the winding of relay 167 the left-hand alternate contact of relay 166 and the left-hand normal contact of relay 161 to ground. The operation of relay 167 prevents the transmission of a signaling im' ulse from office Z to oilice TV. Relay166 is ocked over a circuit extending from battery through the winding and leftdiand alternate contact of relay 166 to the left-hand normal contact of relay 161 to ground, and

relay 167 is also looked over a similar circuit.

After the signaling impulse has beentransmitted, relays 61 and 68 at office W remain in an operative condition while relays 166 and 167 atofiice Z remain inan operated condition.

Operator at ofiiee Z answers a caZZ being 8 extended oner Zine circuit 0.

The operator. at oifice Z observing the lighted condition of lamp 163 inserts plug 13 of a link circuit 1) thereat into jack 160, thereby causing the operation of relays 1 1 and 161 over a circuit extending from battery through the windingof relay 141, sleeve contacts of plug 13 and jack 160 and the winding of relay 161to ground. The opening of the left-hand normal contact of relay 161 causes the release of relays 166 and 167, thereby extinguishing lamp 163. A signaling impulse for operating relay 6 1is now transmittechin the same manner as previously described in connection with line A, to ofiice W to inform the operator at said oifice thatthe call hasbeenanswered at office Z. By actuating listening key 15 of the selected link circuit D, the operator at oilice Z may communicate with the operator at office W.

Operator at ofiice Z transmits disconnect signal to the operator at 'ofioe W over Zine circuit A.

relay 12 1, the winding of the repeating coil,

winding of relay 125, and the condenser 131 shunting the condenser 132, the upper normal contact of relay 12 1, the tip contacts of jack 120 and plug 13, and the upper alternate contact of ringing key 18 to ground. The closure of theleft-hand contact of relay 125 short circuits the winding of the repeating coil to thereby prevent the ringing current being induced into the outgoing section of the line circuit through such coil. The 010- sure of the right-hand contact of relay 125 causes the operation of relay 130 over a circuit extending from battery through the winding of relay, 130 the right-hand normal contact ,ofrelay 129, the right-hand alternate Contact of relay 128 and the right-hand contact of relay 125 to ground. The locking circuitofrelay128 is opened at middle normalcontact of relay 130. From this point to the energization of relay 24 the operation of transmitting a signal to oiiice 1 V to light lamp 17 is the same as described in connection with the transmission of a si nal to oflice 1V when the operator at otfice Z answered the call on line A. Supervisory relay 16, in the link circuit D associated with the line circuit A, is thereupon operated over .a cirkey 18, the tip contacts of plug 13 and jack 20, and the upper alternate contact of relay 24 to ground. Supervisory lamp 1701? the link circuit D is lighted over a circuit ex tending from battery through the contact of relay 14, the normal contact of listening key 15, and the. lower contact of relay 16, and the lamp 17 to ground. :Relay16is looked over a circuit'extending from batterythrough the contact of relay 14, the normalcontact of relay 15, the upper contact of relay 16 and the right-hand winding of relay 16,.to ground.

The illumination of lamp 17 serves as a disconnect signal to the operator at office 'W who may thereupon remove the plug 13 from the jack 20, causing the release of relay 16, to extin uish the lamp 17 and ofrela-ys 14 and 21, the release of the latter relay also causing the release of relay 28. The opening of the middle alternate contact of relay 21 introduces a break in the circuit holding relay 1, but the latter relay .doesnot release at this time due to the closed conditions of the middle alternate contacts of relays 41 and 61. Theremoval of the plug 13 of the link circuit D from the jack 120 at office Z also causes the release'ot relays 14', 121 and 128, and although the opening of the middle.

contact of relay 121 introduces a break. in the circuit of relay 101, the latter relay is maintained operated due to the continued closure of the middle alternate contacts of relays 141 and 161. i

Operator at (If/ice Z transmits disconnect signal to the operator at ofiice W over Zine circuit B.

Upon the completion of the conversation,

the operator at office Z actuates ringing key 18, causing the operation of relay 145 over a circuit extending from the source of alter- 152, the upper normal 'contact'oit relay 144,

the tip contacts of jack 140 and plug land the upper alternate contact of'key 18' to ground. The closure of the left-handj c'ojntact of relay 145 short-circuits the winding line circuit B.

of the repeating coil thereby effectually preventing the induction of the ringing current into the out-goingsection of the phantom The closure of the righthand contact of relay 145 causes the opera- ,tion of relay 150 over a circuit extending from battery through the winding of relay 150, the lefthand normal contact of relay 149, the right-hand alternate contact of reley 148, and the right-hand contact of relay 145 to ground. Relay 149 operates over a circuit extending from battery through the alternate contact of relay 150. the winding of relay 149 and the left-hand normal contact of relay v130 to ground. The opening ofthe lett-hand normal contact of relay 149 releases relay 150 and the subsequent open ing of the alternate contact of the latter relay causes the release of relay 149. However, durin the interval that relay 149 is operated a circuit is completed from the negative terminal. of the 120 volt source of current through the contact of relay 147, the right-hand alternate contact of relay 149, the right-hand normalcontact of relay 129, the upper winding bridged around relay 134, the simplexed conductors of the line circuit A leading from oitice Z to oitice Y, the winding of. relay 86, the lower winding bridged around relay 86, and the normal contacts of relays 82 and 83in series, to

ground. 'The direction of current flow through this circult is such that relay 86 closes its upper contact to cause the oper-,

ation of relay 84 over an obvious circuit.

The closure of the right-hand alternate contact of relay 84 produces no material .efilect upon the system while the closure of the left-hand alternate contact thereof completes,'duringthe continuation of the impulse, a circuit extending "from the negative terminal of the 120 volt source of current through the left-hand alternate contact of relay 84, the upper bridged winding around relay 81, the simplexed conductors of line circuit A extending from oilice Y to oflice X, the Winding of relay 5, the simplexed conductors of the line circuit A. extending from oflice X to office 1V the winding of relay 34, the lower winding bridged therearound, the left-hand normal contact of relay 29 and the left-hand normal contact of relay v49, to ground. The direction or current flowing through the last-mentioned circuit causes relay 5 to .close its left-hand contact and relay 34 to close its upper contact. The operation of relay 5 does not change the conditions existing at oltice X inasmuch as relay 7 remains locked independent of relay 5. The closure of the upper contact of relay 34, causes the operation of relay 44 over a circuit extending from battery through the winding of relay 44, the left-hand alternate contact of relay 41 and the upper contact of relay 34 to greund. Therefore dub ing the continuation of the impulse a circult is completed extending from the source of alt crnatingcurrent through the lower alternate contact 01: relay il/r, the ring con tacts of jack l0 and plug 13; the lower normal contact of key 18, the left-hand Winding of: supervisory relay .16, the condenser 19, the upper normal contact of key 18, tip contacts of plug 13 and jack 4:0, and the upper alternate contact of relay ll, to ground. Relay 16, in responding thereto causes the lighting of lamp 1? over a circuit extending from battery through the contact of relay 1 1-, the normal contactof key 15, the lower contact of relay 16, and the lamp 17 to ground. As in'the previous case, relay 16 is locked over a circuit extending from battery through the contact ofrelay 14, the normal contact of key 15, the upper contact of relay 16, and the right-hand inding of such relay to round. In re sponse to the illumination oil the lamp 17,

the operator office "W removes the plug- 13 from the ack to release relays 16, 1 1,

11' and 1-8 at oilice W, and by opening the middle alternate contact of relay l1, introalternate contact of relay 61.

duces another break in the circuit controls ling relay 1, which, however still remains energized due to the ground at the middle In a similar manner the removal ofthe plug 13 rom the jack 1 10 at office Z cau'ses'the release of relays 14:, 141 and 1 18 and intro uces other break in the circuit controlling relay 101. i I

Operator at ofiicc Z transmits a disconnect signal to the operator at ofiice W ooer time Zine circuit 0.

Upon the completion of the conversation over line circuit C the operator at office Z actuates ringing key 18 of the link circuit associated therewith to completea circuit e:;-. tending from the source of alternating current through the lower alternate contact-oil key 18, therinp; contacts of plug and jack 160, the lowennorrnal contact of relay 164:, one Winding of the repeating coili the Winding of relay 165 and the condenser 1' l. shunted around condenser 172, the u. normal ontact of relay 164a the tip con of jack and plug 13 and theuppefi' a! responds to such current and the clos of the left-hand contact thereof short-circuits the Winding of the repeating coil to effectually prevent the inducing: of the altcn nate current into the outgoing section otthe line circuit. The closure of the right-hand contact of relay 165 causes the operation of relay over a circuit cxtendingtrorn battery through the Winding of relay 170. theleft-hand normal contact of relay 169 "the right-hand alternate contact of 163 and righnhand a circuit is completed independen ground. curt cs:

clay 169 then operates over a ciring" from butt 1 through the alternate contact of relay 1'70,

of relay 1G9 releases relay 1'70 which in turn opens the opera circuit of relay 169. However, durin the operation of relay 169, from the positive ter minal of the 120 volt source of current through the normal contact of relay 161 the right-handalternate contact of relay 169 the uppersv incline bridged around relay 174 the simpleiced conductors of line circuit C extending from,oihcc Z to other; Y, the Wind;

mg of relay 96 and upper Winding bridged thcrearound. and the normal contacts ot relaysOQ and in series to ground. The direction of current flowing through this circuit .is such that relay closesits lower contact to cause the operation of relay 95 over anj'ohvious circuit The closure oi the left-hand contact of relay 95 establishes a circuit during the continuation ot' pulse which cxtendsironi the-posi mina'l to the 120 olt source of current through the letnhand alternate contact of relay 95, the lettt-haiul normal. contact of relay 94:, the lower Winding bridged around the winding of relay 91', the siinplened conduct-ens oil? line circuit- C- extendingfrom office 1 to otlice Ill-the Winding of-relay 6, the sunplenedconductors of line circuit C extending inom oilice X to ofiicelV Winding of relay 7 the lower Winding hridged-therearound, the left-hand normal contact or". re-

lay and the righthand alternate contact of relay 1 to grouiid. Although the current flOWlilQf through this circuit causes relay 6 to close its left-hand contact no collect is pro duccd upon the system since relay 7 is locked of relay However, the current flowing through the winding of relay "1" l causes it to. close its lower contact thereby causing the operation of relay'Gl, over a circuit extendingfrom battery through the Winding ofrelay 64 the lath hand alternatecontoct of relay 61. and the lower contact otrelsr 74%. to ground, Therefore, during the continuation of the impulse ablished "from the source of I through the lower alter- G-l, the ring contacts of jacl- 60 and "plug 13. the lower normal con tact of l: 1 18, the left-hand Winding of re lay 16, the condenser 19 the upper normal contact of key 18, the tip contacts of plug .13 and jacl: 60 and-the upper alternate contact of relay 64- to ground. Belay 16 causes the lighting .01 supervisory lamp 17 as in theprevious cases and is locked over a circuit similar to that described in the other instances. 'In response to the illumination of the 1 operator at otiioe /V removes plug from jack 60, causing the re 92 over an obvious circuit.

lease of relays 16, 1a, 61 and 68, as in connection with the other line circuits, while the removal of the plug 13 from the jack 160 also causes the release of relays 14, 161 and 168, at office Z in a manner similar to that previously described. In addition to these operations, however, the opening of the middle alternate contact of relay 61 introduces a final break in the circuit of relay 1, causing such relay to release. The release of relay 1 causes the release of relay 2 but due to the fact that the latter-mentioned relay is slow in releasing, a temporary circuit is established extending from the negative terminal of the 120 volt source of current through the alternate contact of relay 2, the normal contact of relay 1, the left-hand normal contact of relay 69, the upper bridged Winding around relay 74, the simplexed conductors of line circuit C, extending from office W to office X, the winding of relay 6, the simplexed conductors of line circuit C extending from oflice. X to ofiice Y, the. winding of relay 91 and the upper Winding bridged therearound, the normal contacts of relays 94 and 95 in series to ground. The direction of current flowing through this circuit is such as to cause relay 6 to close its right-hand contact and relay 91 to close its upper contact. The closure of the righthand contacts of relay 6 causes the operation of relay 8 over an obvious circuit and the opening of the contact thereof releases relay 7. The opening of the middle and right hand contacts of relay 7 disables the filament battery supply circuits for repeaters 'RAl and RC1 at ofiice X. The closure of the upper contact of relay 91 operates relay The opening of the left-hand normal contact of relay 92 releases relay 90 and the opening of the middle and right-hand contacts thereof disables the filament battery supply circuit of repeaters RA2 and RC2 at office Y. Although the closure of the right-hand alternate contact of relay 92 completes a circuit extending from the negative terminal of the 120 volt source of current through the right-hand alternate contact of relay 92, the lower bridged winding around relay 96, the simplexed conductors of line circuit C, extending from office Y to oflice Z the winding of relay 174, the lower winding bridged therearound, the left-hand normal contact of relay 169, the left-hand normal contact of relay 101, and the normal contact of relay 102 to ground, no effect is produced upon the system due to the direction of flow of the current.

What is claimed is:

1. In a system comprising a plurality of lines and a repeater, the method of operating and disabling the repeater which comprises transmitting an impulse over any one of the lines, causing the impulse to render the repeater operative, transmitting an impulse current over only one of the lines and causing the second-named impulse to disable the repeater.

2. In a telephone system, a plurality of transmission lines, repeaters associated with certain of said lines, signaling circuits connected to certain 01"" said lines, means controlled over said signaling circuits for rendering said repeaters effective, and means controlled over only one of said signaling circuits for disabling said repeaters.

3. In a telephone system, a plurality of transmission lines, repeaters associated with certain of said lines, signaling circuits connected to certain of said lines, means controlled over said signaling circuits for rendering said repeaters efiective, and means common to said transmission lines and effective to transmit an impulse over only one of said signaling circuits for disabling said repeaters.

4;. In a telephone system, a plurality of transmission lines, signaling circuits connected to certain of said lines, repeaters associated with certain of said lines, means for transmitting signaling impulses over said signaling circuits when calls are initiated on said lines and means for transmitting an impulse over only one of said signaling circuits for controlling said repeaters.

5. In a telephone system, a plurality of transmission lines, signaling circuits connected to certain of said lines, repeaters asseciated with certain of said lines, means for transmitting signaling impulses over said signaling circuits when calls are initiated on said lines, and means common to said lines for transmitting an impulse over only one of said signaling circuits for rendering said repeaters inefiective.

6. In a telephone system, a plurality of transmission lines, repeaters associated with certain of said lines, means for producing impulses to be transmitted over certain of said lines when a call is initiated, a signaling circuit common to certain of said lines and connected to one of the lines over which impulses are to be transmitted, a second signaling circuit associated with another of said lines, means responsive to impulses transmitted over either of said signaling circuits for rendering said repeaters effective and responsive to an impulse over only one of said circuits for disabling said repeaters, and means responsive to certain of said; impulses tor indicating the particular line taken for the initiation of a call.

7. In a telephone system, physical and phantom lines, repeaters associated with the physical lines, means for producing impulses to be transmitted over said physical lines when calls are initiated on said lines, a signaling circuit common to certain of said lines and connected to one of the physical lines, a second signaling circuit associated with the other physical line, means responsive to impulses transmitted over either of said signaling circuits for rendering said repeaters eflective and responsive to an impulse over only one of said circuits for disabling said repeaters, and means responsive to certain of said impulses for indicating the particular line taken for the initia- 10 tion of a call.

8. The method which comprises transmitting impulses over a number of lines, rendering eflective a plurality of repeaters in response to one of said impulses, translating said impulses into signals, transmitting an impulse over only one of said lines, and disabling said repeaters in response to the second-named impulse.

In witness whereof, I hereunto subscribe my name this 26th day of December A. 1)., 20

I LOUIS A. MORTIMER. 

